Well, it didn't start out in the piston. Must have been sitting on the crank scarper and windage tray areas. Got pulled up through the cam area when I pulled the crank around. Not sure if I want to reuse the oil pan. Rust from chipmunk urine, I guess. Internals look good so far.
2 squirrels climb into a wedge block for a beer...
Just read your post and hate to see this set back. (Should put a squirrel powered decal on scoop). But how did the squirrel get in the oil pan? Was the timing cover off or something else left off for a while? That looks like it has been there for a while with the rust on the pan. Hope you get it going soon.